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Synthesis and decomposition mechanisms of Mg2FeH6 studied by in-situ synchrotron X-ray diffraction and high-pressure DSC

Polanski, M.; Nielsen, T. K.; Cerenius, Yngve LU ; Bystrzycki, J. and Jensen, T. R. (2010) In International Journal of Hydrogen Energy 35(8). p.3578-3582
Abstract
Synthesis and decomposition mechanisms of ternary Mg2FeH6 were investigated using in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high-pressure differential scanning calorimetry (HP-DSC). Two routes for synthesis of Mg2FeH6 were studied. The first utilizes a ball-milled homogeneous MgH2-Fe powder mixture and the second uses a mixture of Fe and Mg formed by decomposition of the ternary hydride, Mg2FeH6. In both cases the reaction mixture was sintered in a temperature range from RT to 500 degrees C under a hydrogen pressure of 100-120 bar. The reaction mechanisms were established using in-situ SR-PXD. The formation of Mg2FeH6 consists of two steps with MgH2 as an intermediate compound, and the presence of magnesium was... (More)
Synthesis and decomposition mechanisms of ternary Mg2FeH6 were investigated using in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high-pressure differential scanning calorimetry (HP-DSC). Two routes for synthesis of Mg2FeH6 were studied. The first utilizes a ball-milled homogeneous MgH2-Fe powder mixture and the second uses a mixture of Fe and Mg formed by decomposition of the ternary hydride, Mg2FeH6. In both cases the reaction mixture was sintered in a temperature range from RT to 500 degrees C under a hydrogen pressure of 100-120 bar. The reaction mechanisms were established using in-situ SR-PXD. The formation of Mg2FeH6 consists of two steps with MgH2 as an intermediate compound, and the presence of magnesium was not observed. In contrast, the decomposition of Mg2FeH6 was found to be a single-step reaction. Additionally, both reactions were investigated using HP-DSC under similar conditions as in the SR-PXD experiments in order to estimate reaction enthalpies and temperatures. Mg2FeH6 was found to form from MgH2 and Fe under hydrogen pressure regardless of whether the MgH2 was introduced in the mixture or formed prior to creation of the ternary hydride. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
keywords
High-pressure DSC, (ball) milling, Mechanical, Magnesium-iron ternary hydride, Magnesium hydride, Iron, In-situ synchrotron radiation powder, X-ray diffraction
in
International Journal of Hydrogen Energy
volume
35
issue
8
pages
3578 - 3582
publisher
Elsevier
external identifiers
  • wos:000277463600047
  • scopus:77950460584
ISSN
1879-3487
DOI
10.1016/j.ijhydene.2010.01.144
language
English
LU publication?
yes
id
126d847f-1bd3-489a-8b56-028115f60aff (old id 1618580)
date added to LUP
2010-06-18 15:39:50
date last changed
2018-12-09 03:42:09
@article{126d847f-1bd3-489a-8b56-028115f60aff,
  abstract     = {Synthesis and decomposition mechanisms of ternary Mg2FeH6 were investigated using in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high-pressure differential scanning calorimetry (HP-DSC). Two routes for synthesis of Mg2FeH6 were studied. The first utilizes a ball-milled homogeneous MgH2-Fe powder mixture and the second uses a mixture of Fe and Mg formed by decomposition of the ternary hydride, Mg2FeH6. In both cases the reaction mixture was sintered in a temperature range from RT to 500 degrees C under a hydrogen pressure of 100-120 bar. The reaction mechanisms were established using in-situ SR-PXD. The formation of Mg2FeH6 consists of two steps with MgH2 as an intermediate compound, and the presence of magnesium was not observed. In contrast, the decomposition of Mg2FeH6 was found to be a single-step reaction. Additionally, both reactions were investigated using HP-DSC under similar conditions as in the SR-PXD experiments in order to estimate reaction enthalpies and temperatures. Mg2FeH6 was found to form from MgH2 and Fe under hydrogen pressure regardless of whether the MgH2 was introduced in the mixture or formed prior to creation of the ternary hydride. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.},
  author       = {Polanski, M. and Nielsen, T. K. and Cerenius, Yngve and Bystrzycki, J. and Jensen, T. R.},
  issn         = {1879-3487},
  keyword      = {High-pressure DSC,(ball) milling,Mechanical,Magnesium-iron ternary hydride,Magnesium hydride,Iron,In-situ synchrotron radiation powder,X-ray diffraction},
  language     = {eng},
  number       = {8},
  pages        = {3578--3582},
  publisher    = {Elsevier},
  series       = {International Journal of Hydrogen Energy},
  title        = {Synthesis and decomposition mechanisms of Mg2FeH6 studied by in-situ synchrotron X-ray diffraction and high-pressure DSC},
  url          = {http://dx.doi.org/10.1016/j.ijhydene.2010.01.144},
  volume       = {35},
  year         = {2010},
}